Confined Space Rescue



Confined Space Rescue

Training Topics

I Respiratory Protection Anatomy and Physiology

II Confined Space Emergencies

III Toxic Atmosphere Monitoring Equipment

IV Breathing Apparatus Review

VI Lifting Systems

Training Continued:

VII Confined Space Rescue Practical Exercises

References

NFPA 1670 Operations and Training for Technical Rescue Incidents

NFPA 1006 Professional Qualifications for Rescue Technicians

Confined Space and Structural Rope Rescue, Michael Roop/Tom Vines/Richard Wright. Mosby Press 1997

References

OSHA 29 CFR 1910.146 Compliance Directive for Permit Required Confined Spaces

Technical Rescue Field Operations Guide, Tom Pendley. Desert Rescue Research 2000

Respiratory Protection

The Respiratory Process

The exchange of gases (O2 & CO2) between the alveoli & the blood occurs by simple diffusion: O2 diffusing from the alveoli into the blood & CO2 from the blood into the alveoli.

Respiratory Process Cont.

We do this, of course, by breathing - continuously bringing fresh air (with lots of O2 & little CO2) into the lungs & the alveoli.

Breathing is an active process - requiring the contraction of skeletal muscles. The primary muscles of respiration include the external intercostal muscles (located between the ribs) and the diaphragm (a sheet of muscle located between the thoracic & abdominal cavities).

The Respiratory Process

Confined Space Emergencies

Confined Space Fatalities:

__ % due to asphyxiation

__ % of the fatalities are would be rescuers

Ex.-1990: 3 Firefighters die in Pennsylvania from Co poisoning from running portable pump

Example: PA Deaths

On May 1, 1990, a 39-year-old male volunteer firefighter died inside a 33-foot-deep water well in Pennsylvania while attempting to pump water out of the well. Also, two male volunteer firefighters (ages 40 and 20) died attempting rescue.

(other examples)

C-Space Definition

OSHA 29 CFR 1910.146

An OSHA confined space is defined as:

A.-

B.-

C.-

Examples

Examples include but are not limited to:

Permit Required C-Space

A confined space permit is required if the space has one or more of the following hazards:

1.

2.

3.

4.

Non-Permit C-Space

A non-permit required confined space is:

1. Spaces that do not contain,

2. Space in which all the hazards

C-Space Entry Risk Profile

A permit required confined space has less risk if it meets the following criteria:

A. The internal configuration of the space is

Entry Risk Pro-file cont.

B. The victim can be easily

C. Rescuers can pass easily through

D. The space can accommodate

E. All hazards in and around the space

C-Space Entry Risk Profile

A permit required confined space has more risk if any of the following conditions or other hazardous conditions exist

A.

B.

C.-

Entry Risk Profile cont.

D.

(Interpreted from NFPA 1670)

C-Space Hazards

It should always be considered that the most unfavorable situation exists in every confined space and that the danger of -

Hazard Types

Hazards specific to a confined space are dictated by:

1.-

Ex. Damp activated carbon in a filtration tank will absorb oxygen, creating an oxygen deficient atmosphere

Hazard Types cont:

2-:

Such as the fermentation of molasses that creates ethyl alcohol vapors and decrease the oxygen content of the atmosphere

Hazard Types cont:

3-

As in the case of sewer systems that may be affected by rising water, heavier than air gases, or flash floods

The most hazardous kind of confined space is the type that combines limited access and mechanical devices

C-Space Hazard Groups

Confined space hazards can be grouped into the following categories:

1.

2.

3.

4.

Oxygen Deficient Atmosphere

Normal atmosphere composed of % oxygen, % nitrogen and % argon

An atmosphere containing less than % oxygen shall be considered oxygen deficient

*O2 levels inside confined spaces may be decreased as the result of consumption or displacement*

Effects of decreasing O2 Levels

Level of 17 %

Between 14-16 %

Between 6-10 %

Less than 6 %

Consumption of O2

Takes place during ___________ of flammable substances

During bacterial action

During chemical reactions as in the formation of rust

Displacement of O2

Gas that ______________oxygen and therefore reduce the O2 levels

Nitrogen, argon, helium and carbon dioxide are used as inerting agents to displace flammable substances and retard pyrophoric reactions

O2 Enriched Environment

An atmosphere containing more than % of oxygen is oxygen enriched and enhances the flammability of combustibles

Flammable materials such as clothing and hair burn violently when ignited

Flammable Atmospheres

Arise from enriched O2 atmospheres, vaporization of flammable liquids, byproducts of work, chemical reactions or concentrations of combustible dust

Work conducted in a c-space can generate flammable atmospheres

Flammable Atmosphere Terms

________________________is the lowest temperature at which a liquid can form an ignitable mixture in air near the surface of the liquid. The lower the flash point, the easier it is to ignite the material

(at the flash point, the flame does not need to be sustained).

Example

Gasoline has a flash point of -50 degrees F (-45 C) and is more flammable than ethylene glycol (antifreeze) which has a flash point of 111 degrees C (232 F)

Flammable Atmosphere Terms

_____________________ the temperature at which the flame becomes self-sustained so as to continue burning the liquid

The fire point is usually a few degrees _____________________ the flash point

Flammable Atmosphere Terms

____________________________ apply generally to vapors and are defined as the concentration range in which a flammable substance can produce a fire or explosion when an ignition source (such as a spark or open flame) is present

The concentration is generally expressed as percent fuel by volume

UEL/LEL

_____________________________ (UFL) the mixture of substance and air is too rich in fuel (deficient in oxygen) to burn. This is sometimes called the upper explosive limit (UEL)

_____________________________ (LFL) the mixture of substance and air lacks sufficient fuel (substance) to burn. This is sometimes called the lower explosive limit (LEL)

Example UEL/LEL

It is usually quite easy to reach the lower flammable limit. There are numerous cases where individuals have used a solvent, sealer, or other flammable materials in a basement or closed room with inadequate ventilation...and have been injured when the vapors were ignited by a pilot light, electric spark or other ignition source

Example UEL/LEL

Newcastle in September of 2003

A pipe fitter left an acetylene cylinder inside his vehicle over the weekend. Either the cylinder had a small leak or the valve was not fully closed. The flammable limits for acetylene are extremely broad, _____% to ____% in air

When the worker opened the door, an undetermined spark source (the door light switch, light bulb, cellular phone, static etc.) ignited the mixture with catastrophic results

Acetylene Explosion

Flammable Atmosphere Terms

________________________________ (PEL) is the maximum amount or concentration of a chemical that a worker may be exposed to under OSHA Regulations

_________________________________ (TWA) - are an average value of exposure over the course of an 8 hour work shift

Flammable Atmosphere Terms

_____________________________________ (IDLH) atmospheres poses an immediate threat to life, would cause, irreversible adverse health effects, or would impair an individual's ability to escape from a dangerous atmosphere

Flammable Atmospheres

Flammable gases such as

or vapors from hydrocarbons can be trapped in c-spaces

Gases than air will seek lower levels as in pits, sewers, storage tanks/vessels

Flammable Atmospheres

In a closed top tank, lighter than air gases may rise and develop a flammable concentration if trapped the opening

Combustible dust concentrations are found during loading/offloading, conveying grain products, nitrated fertilizers and finely ground chemical products

Toxic Atmospheres

The source of toxic atmospheres encountered in c-spaces may arise from:

Toxic Atmospheres

Carbon Monoxide

Odorless, colorless gas, approximately the same density of air

Formed from incomplete combustion of organic materials

Can be formed from mircobial decomposition of organic materials in sewers/silos and fermentation tanks

Measuring Toxicity

Measured in terms of permissible exposure limit (PEL)

PEL is the concentration of a toxin that most people could safely be exposed to for an 8 hour period

Any toxin in a confined space greater than its PEL is hazardous

Irritant (Corrosive) Atmospheres

Irritant gases vary widely among all areas of industrial activity

They can be found in plastic plants, chemical plants, petroleum industry, tanneries, refrigeration industries, paint manufacturing and mining operations

Irritant (Corrosive) Atmospheres

Prolonged exposure at irritant or corrosive concentrations in a c-space may produce little or no evidence of irritation

Danger in this situation is that worker is usually not aware of any toxic exposure

Examples: nitrogen dioxide, sulfur dioxide, ammonia

Mechanical/Physical Hazards

Vibrations/moving machinery

Augers, hydraulics, steam, etc.

Noise

Noise problems intensified in c-space because interior causes sound to reverberate

May disrupt verbal communication with emergency personnel on the exterior of the space

Toxic Atmosphere Monitoring Equipment

Atmospheric monitoring should take place continuously or at frequent intervals during the rescue operation

All atmospheric monitoring equipment should meet OSHA standards

Equipment should be calibrated according to manufacturer’s recommendations

Atmospheric Testing Procedures

First set of tests should be performed by remote probe prior to entering the space

All levels of the space need to be metered due to (weight of a vapor compared to air)

Principles of Air Monitoring

meters to manufacturer’s spec

If O2 level is not normal, readings will be affected

Spaces may have stratified atmospheres, levels of space must be metered

Allow for air intake in sampling hose/probe, approx. sec per of hose

_________ ppm = ______ %

Meters

Oxygen Levels

According to OSHA, air containing less than 19.5 % or more than 23 % oxygen is unacceptable

If oxygen level is not normal, flammability readings will be effected

Atmosphere Flammability

Measured in the % of the lower explosive limit (LEL)

The LEL is the lowest concentration of a product that will explode or burn when it contacts a source of ignition of sufficient temperature

OSHA -> C-space is hazardous if it contains more than ______ % of the LEL

Lower Explosive Limit LEL

A flammable gas must reach 100 % of its LEL to ignite and burn

Meters are usually calibrated with a flammable gas such as methane, heptane or pentane

Lower Explosive Limit LEL

Methane LEL -> approximately 5 %

Different gases have different LELs

Meter calibrated to methane will give an inaccurate reading for a gas with a different LEL

Meter reading of 10 % or less of the LEL should ensure that an atmosphere is below the LEL of most gases

Common Gas Examples

Methane (CH4):

LEL %, UEL %

Nitrogen (N2):

Common Gases

Carbon monoxide (Co):

PEL =

TWA =

LEL ____%, UEL ____ %

IDLH =Common Gases

Hydrogen Sulfide (H2S):

Odor thresh hold = ppm

LEL = ____ %, UEL = ____ %

Hydrogen Sulfide Cont:

PEL =

TWA =

IDLH =

Toxic Atmospheres

Known materials:

-Use meter specific to that ______________ to test for these products

Unknown materials:

-Use meters to take readings and narrow the spectrum of chemicals

-Broad spectrum analysis

-Colormetric tubes

Hazard Abatement

Hazard Reduction

Reducing or abating hazards of a confined space emergency-

In addition to protective equipment, SCBA, other measures should be taken externally

OSHA requires that measures be taken before permit spaces are entered

Electrical

Usually isolated by a combination of:

1.

2.

Hydraulic

Includes liquids, finely divided solids that if not secured may cause exposure or engulfment

Usually isolated by:

1.

2.

Mechanical

Hazards in the space or introduced into the space

Includes energy from:

Ventilation

Why Ventilate??

When atmospheric conditions is a c-space do not meet the limits for O2, flammability and toxic vapors, the c-space must be ventilated to bring the atmosphere into those limits.

Methods of Ventilation

1.

2.

3.

Positive Pressure (Supply)

Direction of fresh air flow _______ space creating a positive pressure diluting any contaminants by the addition of fresh air

_______________________ operated fans should be used to prevent unacceptable levels of Co into space by use of gasoline blowers

Air flow should be introduced into the space and the flow should be at the level at which rescuers will be working

Positive Pressure

Fan should be allowed to operate long enough to exchange the air content of the space several times

Capacity of fan in cubic feet per minute (CFM) divided into the volume of the space in cubic feet = the time it takes to exchange air one time

Positive Pressure (Supply)

Positive pressure (supply) can force air into space ________times the distance exhaust (negative) pressure can draw it

Examples

Super Vac's AirPac 25 duct canister allows the 25 ft. x 8 in. duct to be easily stored and rapidly deployed

Negative Pressure (Exhaust)

Exhausts contaminants from the space (using negative pressure) by pulling contaminated air out of a space

A slight vacuum is created that can draw other contaminants into the space

May draw flammable gases over motor

Positive-negative/push-pull

Flushes the atmosphere by supplying and exhausting large volumes of air

Two portals must be present, positive air flow into space while negative pressure pulls contaminants out

Most ________________ method for ventilation

Consider where the contaminated exhaust is going and if it will pose an additional hazard

Respiratory Protection

Types of SCBA

OSHA CFR 1910 direct that unless the cause of the emergency can be established as NOT atmosphere related, fresh air breathing apparatus must be worn

Types:

Self contained breathing apparatus (SCBA)

Supplied air respirator (SAR)

Self Contained Breathing Apparatus

Positive pressure since 1983

Prevents contamination of the air inside the face piece if a leak occurs in the face piece’s seal

Limited amount of air supply (based on wearers personal characteristics)

Supplied Air Respirators

During C-space rescue, conventional SCBA’s size often makes it difficult to use

SCBA small enough to pass through narrow openings may limit duration of its air supply to impractical levels

Supplied Air Respirators are a viable option

SAR Components

SAR consists of:

Open circuit face piece

Regulator

Egress cylinder attached via a low-pressure air line to remote source air supply (restricted to maximum distance allowed by manufacturers, usually no more than 300 feet from point of attachment)

SAR Components

OSHA requires an SAR used in an atmosphere that is immediately dangerous to life and health (IDLH) have an additional supply

Must be capable of providing enough air for the wearer to escape the atmosphere in the event the primary supply is interrupted

SAR Components

“Escape” requirement addressed by attaching small breathing air cylinder rated at 5 minutes to the SAR unit

5 minute cylinder are intended to provide enough air for escape although they may be incapable of doing so

SAR

Air Carts

Survivair Air Cart

Contains up to two independently operated 30-,45-, or 60-minute high pressure (4500 psi) cylinders

Or to two independently operated 30 minute low pressure (2216 psi) cylinders

An optional accessory case can hold a variety of Hip-Pac and hose combinations

Survivair Air Cart

Two inlets allow regulated or unregulated external air sources to be used

Built-in manifold has four Foster or Schrader quick-disconnect couplings to supply air for up to four workers

Used in any confined space where an SCBA would reduce or restrict worker movement

OSHA Respiratory Standard

1910.134(e)(3)(iii) requires, when an IDLH atmosphere exists, A stand by man or men with suitable self contained breathing apparatus shall be at the nearest fresh air base for emergency rescue

Safe Respiratory Work Practices

1. Rescuers should immediately

2. Rescuers should wear

3. Minimum capacity of of the source air should be ____________ the volume of the total needs of all rescuers connected to it for the anticipated duration of the rescuer’s entry

Safe Work Practices cont:

4. A minimum team of __________ rescuers should be utilized for all permit space rescue entries

Lifting/Raising Systems

Miller Tripod

Miller Tripods provide a highly portable anchorage system for typical confined space entry and rescue systems

Made of high-strength aluminum, the tripod withstands up to 5,000 lbs of pull yet weights only 42 lbs

Legs lock independently and adjust with integral push pins allowing set up on uneven surfaces

SKED EVAC Tripod

Features aircraft-grade, gold-anodized aluminum legs and a cast-aluminum head

Three heavy-duty rigging anchors have exceptionally large holes for easy attachment and are located in the center

SKED EVAC Tripod

Legs adjust in 5-inch increments for a maximum height of 10 feet and a minimum length for transport of 7 feet

Holes in the feet allow the tripod to be bolted into position

119 inch height / 5,280 lbs (23kN)

SKED EVAC Tripod

Mechanical Advantage Systems

Retrieval Systems

1910.146 (k)(3) requires that retrieval systems be used except when the retrieval equipment would increase the risk to an entrant or would not contribute to the rescue of an entrant.

When a retrieval system is not used, alternate methods of retrieval must be developed.

MA Systems

Rescuer hauler 4:1 system

3-inch double pulley with a cam

rope can move in only one direction when the cam is engaged

allows rescuer to raise a load by pulling on the tail end of the rope, releasing it, and getting another grip

MA Systems

Rescuer hauler 4:1

cam can be released manually by pulling on the attached cord

accommodates rope sizes from 3/8” (10mm) to 1/2” (12/5mm).

Minimum break strength when in use is 12,000 lb

Patient Evacuation Devices

Patient packaging devices that can be used in confined spaces include but are not limited to the following:

Prefabricated Class III Ha

C-Space Rescue

Priority 1: Make the scene safe

Priority 2: Victim contact by Primary Rescuer

C-Space Rescue

Priority 3: Size-up

-

-

-

-

Priority 4: Preparation

-

-

-

C-Space Rescue

Priority 5: Access Victim

-

-

-

Priority 6: Stabilize and package victim

-

-

C-Space Rescue

Priority 7: Evacuate

-

-

-

Priority 8: Response Termination

-

-

-

Rescue Response

Non-IDLH Atmosphere

Incident Commander

Rescue Sector Officer

Entry Supervisor:

Verifies

Determines that

Removes

Terminates entry

Rescue Response

Attendant:

Knows

Knows

Remains

Communicates

Monitors

Calls

Prevents

Performs no

Rescue Response

Entrant (Primary):

Knows

Recognizes

Recognizes

Uses proper

Communicates with

Alerts

Rescue Response

Entrant (Stand-by):

Knows

Recognizes exposure

Recognizes effects of

Uses proper

Communicates with

Alerts attendants of

Rescuer for primary

Rescue Response

Support Personnel:

Safety Officer:

Oversees scene

In matters of safety, has over the incident commander

During rescue, each rescuer should consider him/herself equally responsible for safety

IDLH Atmosphere

Incident Commander

Rescue Sector Officer

Entry Supervisor:

Verifies tests required are complete

Determines that space remains safe during work

Removes unauthorized persons from space area

Terminates entry if conditions are poor/degrading

IDLH Atmosphere

Attendant:

Knows space hazards

Knows effects of exposure

Remains outside space at all times

Communicates with entrant(s)

Monitors entry activities

Calls RESCUE if needed

Prevents unauthorized entry

Performs no conflicting duties

IDLH Atmosphere

Entrant (Primary # 1):

Knows space hazards

Recognizes exposure signs/symptoms

Recognizes effects of exposure

Uses proper PPE

Communicates with attendant

Alerts attendants of hazards

IDLH Atmosphere

Entrant (Primary # 2):

Knows space hazards

Recognizes exposure signs/symptoms

Recognizes effects of exposure

Uses proper PPE

Communicates with attendant

Alerts attendants of hazards

IDLH Atmosphere

Entrant (Stand-by # 1):

Knows space hazards

Recognizes exposure signs/symptoms

Recognizes effects of exposure

Uses proper PPE

Communicates with attendant

Alerts attendants of hazards

Rescuer for primary entrant

IDLH Atmosphere

Entrant (Stand-by # 2):

Knows space hazards

Recognizes exposure signs/symptoms

Recognizes effects of exposure

Uses proper PPE

Communicates with attendant

Alerts attendants of hazards

Rescuer for primary entrant

IDLH Atmosphere

Support Personnel:

Ventilation/metering/air watch/decon, etc.

Safety Officer:

Oversees scene for safety hazards

In matters of safety, has authority over the incident commander

During rescue, each rescuer should consider him/herself equally responsible for safety

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